CAD Online Challenge: Planetary Transmission

VEX Robotics Competition Discussion Online Challenges
#1

Hi everyone!

This year, my team and I created a planetary transmission for the Online CAD Challenge. It would be great if you could go check it out and vote!

Vote Here!

I would also like to talk about some stuff relating to the design:

  • We got the idea from jpearman’s animation of a planetary transmission made from VEX parts. (This idea originally came from this robot if I’m not mistaken)
  • Future revisions of this transmission would have more solid mounting points and alternate gear ratios. Currently, the ratios are 1:1 - 1:4.33 (VEX) and 1:1.25 - 1:5.42 (PT). We would like to change the gears to allow ratios like 1:0.66 - 1:2.5. I believe that all you would have to do is reduce the size of the input sprocket gear.

Please leave a reply if you have any comments or questions.

#2

This is really well-made.

However, from my experience with these as well from what I’ve heard from others, the two motors will end up fighting each other on the torque setting, making that setting basically useless.

Have you tried testing how the transmission responds to different loads?

#3

In the one that we built and tested, we (accidentally) used a bad motor for one of the inputs, which would cause the transmission to stop working after about 1 minute of use. When I tested the torque though, it seemed at least as much as one motor. If I have time tomorrow, I can do a more formal test with a force meter and some decent motors.

Thank you for commenting.

#4